The loot sucks. But then again you are not doing this for the cash.

To get the dude to spawn I went around and made sure I had killed enough of every creature in the place so that there were no numbers next to then in the bestiary(every creature has the second page) expect for the Horse Mare thing. I never left the place. I then went down to the area and killed everyone and exited through the bottom most exit(according to the map). Then turned around and went back in and ran all the way to the T intersection(this is where he spawns). Then as I was running by on about my 20th time he just appeared behind me. I was about to kill him because he looks very much like some of the other enemies...dark mage or something? He is like a floating head with arms...and ram horns. It takes a while to spawn him. I don't think there is a specific way to spawn him other than luck.

In all honesty I was going to leave the area on my last run back and just say screw and come back after I do more hunts and then he appeared. Lucky me.